linux-toradex.git/fs/fuse/cuse.c, branch v5.5

fuse: fix memleak in cuse_channel_open

2019-09-24T13:28:01+00:00

If cuse_send_init fails, need to fuse_conn_put cc->fc.

cuse_channel_open->fuse_conn_init->refcount_set(&fc->count, 1)
                 ->fuse_dev_alloc->fuse_conn_get
                 ->fuse_dev_free->fuse_conn_put

Fixes: cc080e9e9be1 ("fuse: introduce per-instance fuse_dev structure")
Reported-by: Hulk Robot 
Signed-off-by: zhengbin 
Signed-off-by: Miklos Szeredi

fuse: separate fuse device allocation and installation in fuse_conn

2019-09-12T12:59:41+00:00

As of now fuse_dev_alloc() both allocates a fuse device and installs it in
fuse_conn list.  fuse_dev_alloc() can fail if fuse_device allocation fails.

virtio-fs needs to initialize multiple fuse devices (one per virtio queue).
It initializes one fuse device as part of call to fuse_fill_super_common()
and rest of the devices are allocated and installed after that.

But, we can't afford to fail after calling fuse_fill_super_common() as we
don't have a way to undo all the actions done by fuse_fill_super_common().
So to avoid failures after the call to fuse_fill_super_common(),
pre-allocate all fuse devices early and install them into fuse connection
later.

This patch provides two separate helpers for fuse device allocation and
fuse device installation in fuse_conn.

Signed-off-by: Vivek Goyal 
Signed-off-by: Miklos Szeredi

fuse: add fuse_iqueue_ops callbacks

2019-09-12T12:59:41+00:00

The /dev/fuse device uses fiq->waitq and fasync to signal that requests are
available.  These mechanisms do not apply to virtio-fs.  This patch
introduces callbacks so alternative behavior can be used.

Note that queue_interrupt() changes along these lines:

  spin_lock(&fiq->waitq.lock);
  wake_up_locked(&fiq->waitq);
+ kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
  spin_unlock(&fiq->waitq.lock);
- kill_fasync(&fiq->fasync, SIGIO, POLL_IN);

Since queue_request() and queue_forget() also call kill_fasync() inside
the spinlock this should be safe.

Signed-off-by: Stefan Hajnoczi 
Signed-off-by: Miklos Szeredi

cuse: convert init to simple api

2019-09-10T14:29:49+00:00

This is a straightforward conversion.

Signed-off-by: Miklos Szeredi

cuse: fix broken release

2019-09-02T09:07:30+00:00

The inode parameter in cuse_release() is likely *not* a fuse inode.  It's a
small wonder it didn't blow up until now.

Signed-off-by: Miklos Szeredi

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428

2019-06-05T15:37:16+00:00

Based on 1 normalized pattern(s):

  this file is released under the gplv2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 68 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Armijn Hemel 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de
Signed-off-by: Greg Kroah-Hartman

fuse: convert printk -> pr_*

2019-04-24T15:05:06+00:00

Functions, like pr_err, are a more modern variant of printing compared to
printk. They could be used to denoise sources by using needed level in
the print function name, and by automatically inserting per-driver /
function / ... print prefix as defined by pr_fmt macro. pr_* are also
said to be used in Documentation/process/coding-style.rst and more
recent code - for example overlayfs - uses them instead of printk.

Convert CUSE and FUSE to use the new pr_* functions.

CUSE output stays completely unchanged, while FUSE output is amended a
bit for "trying to steal weird page" warning - the second line now comes
also with "fuse:" prefix. I hope it is ok.

Suggested-by: Kirill Tkhai 
Signed-off-by: Kirill Smelkov 
Reviewed-by: Kirill Tkhai 
Signed-off-by: Miklos Szeredi

fuse: clean up aborted

2019-02-13T12:15:14+00:00

The only caller that needs fc->aborted set is fuse_conn_abort_write().
Setting fc->aborted is now racy (fuse_abort_conn() may already be in
progress or finished) but there's no reason to care.

Signed-off-by: Miklos Szeredi

fuse: Add fuse_inode argument to fuse_prepare_release()

2019-02-13T12:15:13+00:00

Here is preparation for next patches, which introduce new fi->lock for
protection of ff->write_entry linked into fi->write_files.

This patch just passes new argument to the function.

Signed-off-by: Kirill Tkhai 
Signed-off-by: Miklos Szeredi

fuse: Support fuse filesystems outside of init_user_ns

2018-03-20T16:11:44+00:00

In order to support mounts from namespaces other than init_user_ns, fuse
must translate uids and gids to/from the userns of the process servicing
requests on /dev/fuse. This patch does that, with a couple of restrictions
on the namespace:

 - The userns for the fuse connection is fixed to the namespace
   from which /dev/fuse is opened.

 - The namespace must be the same as s_user_ns.

These restrictions simplify the implementation by avoiding the need to pass
around userns references and by allowing fuse to rely on the checks in
setattr_prepare for ownership changes.  Either restriction could be relaxed
in the future if needed.

For cuse the userns used is the opener of /dev/cuse.  Semantically the cuse
support does not appear safe for unprivileged users.  Practically the
permissions on /dev/cuse only make it accessible to the global root user.
If something slips through the cracks in a user namespace the only users
who will be able to use the cuse device are those users mapped into the
user namespace.

Translation in the posix acl is updated to use the uuser namespace of the
filesystem.  Avoiding cases which might bypass this translation is handled
in a following change.

This change is stronlgy based on a similar change from Seth Forshee and
Dongsu Park.

Cc: Seth Forshee 
Cc: Dongsu Park 
Signed-off-by: Eric W. Biederman 
Signed-off-by: Miklos Szeredi